Herbicidal 1-substituted methyl-tetrazolinones

ABSTRACT

Novel 1-substituted methyltetrazolinones of the formula (I) ##STR1## wherein R 1  represents a 5-membered heterocyclic radical which has 1 to 3 heteroatoms selected arbitrarily from the group consisting of N, O and S and which is optionally substituted by halogen and/or C 1-4  alkyl, or represents oxiran-2-yl, optionally chloro-substituted pyridyl or C 1-4  alkyl-S(O) m  --wherein m represents 0, 1 or 2, or represents a C 3-6  alicyclic hydrocarbon radical; R 2  and R 3  represent, independently of one another, C 1-4  alkyl, C 3-7  cycloalkyl or optionally substituted phenyl, or R 2  and R 3  may form, together with the N-atom to which they are bonded, an optionally substituted ring; R 4  represents a hydrogen atom or methyl; and n represents 0 or 1; as well as for their preparation processes and novel intermediates in their production. The inventive compounds of formula (I) are used as herbicides.

The present invention relates to novel 1-substitutedmethyltetrazolinones, processes for, their preparation and their use asherbicides as well as novel intermediates therefore.

It has already been known that certain tetrazolinones possess herbicidalactivity (see EP-A-146,279).

These previously known compounds, however, have not been fullysatisfactory in respect of their herbicidal effect and phytotoxicity oncrop plants.

Now it has been discovered that novel 1-substituted methyltetrazolinonesof the formula (I) ##STR2## wherein R¹ represents a 5-memberedheterocyclic radical which has 1 to 3 heteroatoms selected arbitrarilyfrom the group consisting of N, O and S and which is optionallysubstituted by halogen and/or C₁₋₄ alkyl, or represents oxiran-2-yl,optionally chloro-substituted pyridyl or C₁₋₄ alkyl-S(O)_(m) --wherein mrepresents 0, 1 or 2, or represents a C₃₋₆ alicyclic hydrocarbonradical,

R² and R³ represent, independently of one another, C₁₋₆ alkyl, C₃₋₇cycloalkyl or optionally substituted phenyl, or R² and R³ may form,together with the N-atom to which they are bonded, an optionallysubstituted ring,

R⁴ represents a hydrogen atom or methyl, and

n represents 0 or 1

have surprisingly superior activity.

The compounds of the formula (I) according to the invention can beproduced, for instance, by the following process in which

Process (a)

compounds of the formula (II) ##STR3## wherein R¹, R⁴ and n are definedas above, are reacted with compounds of the formula (III) ##STR4##wherein R² and R³ are defined as above, and

M represents a leaving radical such as chloro or bromo,

in the presence of an inert solvent, and if appropriate in the presenceof a base.

The compounds of the formula (I) according to the invention have strongherbicidal activity and they exhibit very superior herbicidal action aswell as better compatibility with crop plants in comparison to thepreviously known compounds which are similar to those of the formula (I)described in the above EP-A-146,279.

Therefore, the compounds according to the invention are extremely usefulas herbicides.

In this specification, the term "5-membered heterocyclic radical"includes a monovalent radial consisting of a saturated, unsaturated orpartially unsaturated 5-membered heterocyclic ring which has 1 to 3identical or different heteroatoms selected from the group consisting ofN, O and S. Preferably, it represents a monovalent radical consisting ofan unsaturated 5-membered heterocyclic ring having one or two N atom(s)and one O atom or one S atom; two N atoms; or one S atom or O atom.Specific examples thereof include, for example, isoxazolyl, pyrazolyl,1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, thiazolyl, isothiazolyl, thienyl,furyl, imidazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl and1,3,4-thiadiazolyl.

The term "halogen" includes fluorine, chlorine, bromine and iodine,preferably being fluorine, chlorine or bromine.

The term "C₃₋₆ alicyclic hydrocarbon radical" refers to a saturated orpartially unsaturated alicyclic hydrocarbon radical having 3 to 6 carbonatoms, and includes, for example, cycloalkyl such as cyclopropyl,cyclobutyl, cyclopentyl and cyclohexyl; and cycloalkenyl such ascyclopentenyl and cyclohexenyl.

The term "alkyl" refers to an alkyl group which may be straight chain orbranched chain, and includes, for example, methyl, ethyl, n-propyl,iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl andn-hexyl.

The term "cycloalkyl" is a cyclic alkyl radical, and includes, forexample, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

The substituent(s) for the "optionally substituted phenyl" include, forexample, halogen and C₁₋₄ alkyl. Said phenyl can be substituted by atleast 1, preferably 1 to 2 of these substituent(s).

With regard to the phrase "optionally substituted ring which is formedtogether with the N-atom", said ring is a 5- to 6-membered monocyclic orbenzo-condensed polycyclic heterocyclic ring containing at least 1,preferably only 1 N-atom. Examples of the cyclic rings which may beformed by ##STR5## in formula (I) include 1,2-dihydroquinolin-1-yl and1,2,3,4-tetrahydroquinolin-1-yl. These rings may optionally besubstituted and the possible substituents include, for example, C₁₋₄alkyl such as methyl or ethyl and halogen such as fluoro or chloro,preferably being methyl or fluoro.

Preferred compounds of the formula (I) according to the invention arethose wherein

R¹ represents a 5-membered heterocyclic radical which has one or two Natoms and one O atom or one S atom; two N atoms; or one N atom or O atomand which is optionally substituted by chloro and/or methyl, orrepresents oxiran-2-yl, chloro-substituted pyridyl, C₁₋₃ alkylthio,methylsulfinyl, methylsufonyl, cyclopropyl, cyclopentenyl or cyclohexyl,

R² and R³ represent, independently of one another, C₁₋₄ alkyl, C₅₋₆cycloalkyl or optionally substituted phenyl (here the substituent(s)being halogen or C₁₋₄ alkyl), or

R² and R³ may form, together with the N-atom to which they are bonded,optionally substituted 1,2-dihydroquinolin-1-yl or1,2,3,4-tetrahydro-quinolin-1-yl (here the substituent(s) being methylor fluoro),

R⁴ represents a hydrogen atom, and

n represents 0 or 1.

More preferred compounds of the formula (I) according to the inventionare those wherein

R¹ represents isooxazolyl, pyrazolyl, 1,2,5-oxadiazolyl,1,3,4-oxadiazolyl, thiazolyl, isothiazolyl, thienyl or furyl, saidradicals optionally being substituted by chloro and/or methyl, orrepresents oxiran-2-yl, 3-pyridyl, 6-chloro-3-pyridyl, methylthio,n-propylthio, isopropylthio, methylsulfinyl, methysulfonyl, cyclopropyl,cyclopentenyl or cyclohexyl,

R² and R³ represent, independently of one another, C₁₋₃ alkyl,cyclohexyl or optionally substituted phenyl (here the substituent(s)being fluoro, chloro, bromo or methyl), or

R² and R³ may form, together with the N-atom to which they are bonded,6-fluoro-2,2-dimethyl-1,2,3,4-tetrahydroquinolin-1-yl,2-methyl-1,2,3,4-tetrahydroquinolin-1-yl,2,2-dimethyl-1,2-dihydroquinolin1-yl,6-fluoro-2,2-dimethyl-1,2-dihydroquinolin-1-yl or2,2-dimethyl-1,2,3,4-tetrahydroquinolin-1-yl,

R⁴ represents a hydrogen atom, and

n represents 0 or 1.

The process (a) for the preparation of the compounds of the aboveformula (I) is represented by the following equation, when, as thestarting materials, for example,1-(3-isooxazolylmethyl)-5(4H)-tetrazolinone andN-isopropyl-N-phenylcarbamoyl chloride are used. ##STR6##

In the above process (a), the compounds of the formula (II) which areused as the starting material are new and can be produced, for instance,by any of the following processes (b) to (f): That is to say by

Process (b)

the process of reacting compounds of the formula (IV) ##STR7## whereinR¹, R⁴ and n are as defined above,

with trimethylsilyl azide in the presence of a catalytic amount of borontrifluoride-ether complex, or

Process (c)

the process of reacting the compounds of the above formula (IV) withsodium azide in the presence of a catalytic amount of ammonium chloridein a polar solvent, or

Process (d)

the process of reacting compounds of the formula (V) ##STR8## werein R¹,R⁴ and n are as defined above,

with trimethylsilyl azide in the presence of a catalytic amount of borontrifluoride-ether complex, or

Process (e)

the process of reacting compounds of the formula (VI) ##STR9## whereinR¹, R⁴ and n are as defined above,

with compounds of the formula (VII) ##STR10## wherein M represents ahydrogen atom or methyl, or

Process (f)

when

R¹ represents a radical other than C₁₋₄ alkyl-S(O)_(m) --, the processof reacting compounds of the formula (VIII) ##STR11## wherein R¹ 'represents the radical as defined for R¹, with the exception of C₁₋₄alkyl-S(O)_(m) --, and

R⁴ and n are as defined above,

with sodium periodate in the presence of a catalytic amount of osmiumoxide [OsO₄ ].

Alternatively, the compounds of the formula (I) wherein R¹ representsalkyl(C₁₋₄)sulfinyl or alkyl(C₁₋₄)sulfonyl, can be produced by oxidizingthe compound wherein R¹ corresponds to alkyl(C₁₋₄)thio according to ageneral oxidation method to thereby easily obtain the compound havingthe corresponding alkyl(C₁₋₄)sulfinyl or the compounds having thecorresponding alkyl(C₁₋₄)sulfonyl.

Alternatively, the compounds of the formula (I) wherein R¹ representsoxiran-2-yl can be obtained by oxidizing1-(2-propenyl)-4-(N,N-disubstituted carbamo-yl)-5(4H)-tetrazolinone withm-chloroperoxybenzoic acid as shown by the later-described SynthesisExample 5, and the compounds of the formula (I) wherein R¹ represents3-methyl-2-isoxazolin-5-yl can preferably be obtained by a conventionalmethod described in Houben-Weyl, 1985, vol. E5, pp. 1591-1610, as shownby the later-described Synthesis Example 6, in which the tetrazolinoneas the reactant is a known compound described in Japanese PatentLaid-open Hei 8-259547.

In the above processes (b) and (c), the compounds of the formula (IV)used as the starting materials include isocyanates known in the field oforganic chemistry and can be synthesized, for example, by the processdescribed in "Shin Jikken Kagaku Koza (New Experimental ChemistryCourse)" edited by Japanese Chemical Society, Vol. 14, pp. 1490-1503(published by Maruzen on Dec. 20, 1977).

In the above process (d), the compounds of the formula (V) used as thestarting materials also include acid chlorides known in the field oforganic chemistry and can be synthesized, for example, by the processdescribed in Shin Jikken Kagaku Koza (New Experimental ChemistryCourse)" edited by Japanese Chemical Society, Vol. 14, pp. 1104-1120(published by Maruzen on Dec. 20, 1977). For example, they can easily beobtained by reacting carboxylic acids represented by the formula (IX),##STR12## wherein R¹, R⁴ and n are as defined above,

with thionyl chloride as a halogenating agent.

The compounds of the above formula (IX) can be synthesized, for example,by the process described in "Shin Jikken Kagaku Koza (New ExperimentalChemistry Course)" edited by Japanese Chemical Society, Vol. 14, pp.921-1000 (published by Maruzen on Dec. 20, 1977), or by hydrolyzing thecorresponding carboxylic acid esters.

In the above process (e), the compounds of the above formula (VI) can besynthesized, for example, by reacting, compounds of the formula (XI)##STR13## wherein R¹, R⁴ and n are as defined above,

with sodium azide, according to the process described in Berichte, Vol.28, pp. 74-76 (1895).

The dithiocarbamic acid esters of the above formula (XI) can easily beobtained, for example, by reacting methanethiol with compounds of theformula (XII) ##STR14## wherein R¹, R⁴ and n are as defined above,

or by reacting compounds of the formula (XIII) ##STR15## wherein R¹, R⁴and n are as defined above,

with carbon disulfide, and further reacting with a methylating agentsuch as dimethyl sulfate or iodomethane.

The compounds of the above formula (XII) can be produced by, forexample, the process described in "Shin Jikken Kagaku Koza (NewExperimental Chemistry Course)" edited by Japanese Chemical Society,Vol. 14, pp. 1503-1509 (published by Maruzen on Dec. 20, 1977).

The compounds of the above formula (XIII) can also be produced by, forexample, the process described in "Shin Jikken Kagaku Koza (NewExperimental Chemistry Course)" edited by Japanese Chemical Society,Vol. 14, pp. 1332-1399 (published by Maruzen on Dec. 20, 1977).

In the above process (e), the compounds of the formula (VII) used asstarting materials are known per se and specific examples thereofinclude ethylene oxide or 1,2-epoxypropane.

In the above process (f), the compounds of the formula (VIII) used asstarting materials can easily be obtained by, for example, reacting1-ethenyl-5(4H)-tetrazolinone with compounds of the formula (XIX)##STR16## wherein R¹, R⁴ and n are as defined above, and

Hal represents halogen.

The 1-ethenyl-5(4H)-tetrazolinone used in the above reaction is acompound known per se and the compounds of the formula (XIX) are alsowell known in the field of organic chemistry.

Typical examples of the compounds of the formula (II) are as follows:

1-(1-cyclopentenylmethyl)-5(4H)-tetrazolinone,

1-(2-tetrahydrofurfuryl)-5(4H)-tetrazolinone,

1-(5-methyl-3-isooxazolylmethyl)-5(4H)-tetrazolinone,

1-(3-isooxazolylmethyl)-5(4HI)-tetrazolinone,

1-(3,5-dimethyl-4-isooxazolylmethyl)-5(4H)-tetrazolinone,

1-(5-chloro-1,3-dimethyl-4-pyrazolylmethyl)-5(4H)-tetrazolinone,

1-(5-isooxazolylmethyl)-5(4H)-tetrazolinone,

1-(4-methyl-1,2,5-oxadiazol-3-ylmethyl)-5(4H)-tetrazolinone,

1-(4-chloro-5-isoxazolylmethyl)-5(4H)-tetrazolinone,

1-(5-methyl-1,3,4-oxadiazol-2-ylmethyl)-5(4H)-tetrazolinone,

1-[2-(3-methylisoxazol-5-yl)-ethyl]-5(4H)-tetrazolinone,

1-[1-(3-methylisoxazol-5-ylmethyl)-ethyl]-5(4H)-tetrazolinone,

1-(cyclohexylmethyl)-5(4H)-tetrazolinone,

1-(cyclopropylmethyl)-5(4H)-tetrazolinone,

1-(6-chloro-3-pyridylmethyl)-5(4H)-tetrazolinone,

1-(4-thiazolylmethyl)-5(4H)-tetrazolinone,

1-(4-isothiazolylmethyl)-5(4H)-tetrazolinone,

1-methylthiomethyl-5(4H)-tetrazolinone,

1-n-propylthiomethyl-5(4H)-tetrazolinone, etc.

On the other hand, the compounds of the formula (III) which are reactedwith the compounds of the above formula (II) are carbamoyl chlorideswhich are well known in the field of organic chemistry. Typical examplesthereof are as follows:

N,N-diethylcarbamoyl chloride,

N-cyclohexyl-N-ethylcarbamoyl chloride,

N,N-di-isopropylcarbamoyl chloride,

N-ethyl-N-isopropylcarbamoyl chloride,

N-methyl-N-isopropylcarbamoyl chloride,

N-isopropyl-N-phenylcarbamoyl chloride,

N-4-fluorophenyl-N-isopropylcarbamoyl chloride,

N-4-chlorophenyl-N-isopropylcarbamoyl chloride,

N-isopropyl-N-p-tolylcarbamoyl chloride,

N-4-bromophenyl-N-isopropylcarbamoyl chloride,

2,2-dimethyl-1,2,3,4-tetrahydroquinolin-1-yl carbonyl chloride,

2-methyl-1,2,3,4-tetrahydroquinolin-1-yl carbonyl chloride,

N-ethyl-N-phenylcarbamoyl chloride,

N-n-propyl-N-phenylcarbamoyl chloride,

N-cyclohexyl-N-isopropylcarbamoyl chloride,

2,2-dimethyl-1,2-dihydroquinolin-1-yl carbonyl chloride,

6-fluoro-2,2-dimethyl-1,2-dihydroquinolin-1-yl carbonyl chloride,

6-fluoro-2,2-dimethyl-1,2,3,4-tetrahydroquinolin-1-yl carbonyl chloride,etc.

The reaction in the process (a) may usually be carried out in an organicsolvent which is inert to the reaction. Examples of the inert organicsolvents useful for the reaction include aliphatic, alicyclic andaromatic hydrocarbons (which may optionally be chlorinated) such aspentane, hexane, cyclohexane, petroleum ether, ligroin, benzene,toluene, xylene, dichloromethane, chloroform, carbon tetrachloride,1,2-dichloroethane, chlorobenzene and dichlorobenzene; ethers such asdiethyl ether, methyl ethyl ether, di-isopropyl ether, dibutyl ether,dioxane, dimethoxyethane (DME), tetrahydrofuran (THF) anddiethyleneglycol dimethyl ether (DGM); nitrites such as acetonitirileand propionitrile; acid amides such as dimethylformamide (DMF),dimethylacetamide(DMA), N-methylpyrrolidone,1,3-dimethyl-2-imidazolidinone and hexamethylphosphoric triamide (HSPA);and others.

The process (a) can be carried out in the presence of a base and thepreferred examples of the useful bases include 4-dimethylaminopyridine(DMAP).

In the case of using DMAP as a base, the reaction in the process (a) canbe carried out generally under a normal pressure at a temperature ofabout -10 to about 200° C., preferably about 25 to about 140° C., but itmay also be optionally operated under an elevated or reduced pressure.

Further, the reaction in the process (a) can also be carried out usingbases other than DMAP and such bases are exemplified by inorganic salts(such as sodium carbonate, potassium carbonate, sodium hydroxide,potassium hydroxide, etc.); alkylalcoholates (such as sodium methoxide,sodium ethoxide, potassium-tert-botoxide, etc.); sodium hydroxide;potassium hydroxide; lithium hydroxide; organic bases (such astriethylamine, 1,1,4,4-tetramethylethylenediamine, N,N-dimethylaniline,pyridine, etc.); and others.

In the case of carrying out the reaction by use of such bases, thecompound of the formula (1) can selectively be obtained by using DMAP asa catalyst.

The reaction temperature in this reaction is generally within a range ofabout 0 to about 150° C., preferably about 25 to about 100° C. Thereaction should preferably be carried out under a normal pressure, butit may also be optionally operated under an elevated or reducedpressure.

Thereupon, the compound of the formula (I) can be obtained by, forexample, reacting about 1 to about 1.5 moles of the compound of theformula (III) with 1 mole of the compound of the formula (II) in thepresence of about 1 to about 1.5 moles of DMAP as a base, in the inertsolvent as mentioned above. Alternatively, the compound of the formula(I) can also be obtained by reacting about 1 to about 1.5 moles of thecompound of the formula (III) with 1 mole of the compound of the formula(II) in the presence of about 0.01 to about 0.3 mole of DMAP as acatalyst and about 1 to about 1.5 moles of a base, for instance,potassium carbonate, in the inert solvent as mentioned above.

The compound of the formula (I) thus produced can be isolated andpurified by means of, for instance, crystallization, chromatography andthe like.

On the other hand, the above process (b) can be conducted using borontrifluoride ethyl ether complex as a catalyst. The reaction temperaturemay be set up to generally about 0 to about 200° C., preferably about 50to about 150° C. Further, the reaction should preferably be carried outunder a normal pressure, but it may also be optionally operated under anelevated or reduced pressure.

The process (b) can be conducted by reacting about 1 to about 2 moles oftrimethylsilyl azide with 1 mole of the compound of the formula (IV) inthe presence of about 0.005 to about 0.01 mole of boron trifluorideethyl ether complex as a catalyst.

Further, the reaction in the process (c) can be carried out usually in apolar solvent and the useful polar solvents are exemplified by acidamides such as dimethylformamide, dimethylacetamide, etc.; andsulfoxides such as dimethyl-sulfoxide, sulfolane, etc. The reactiontemperature is generally about 0 to about 200° C., preferably about 20to about 150° C. The reaction should preferably be carried out under anormal pressure, but it may also be optionally operated under anelevated or reduced pressure.

The process (c) can generally be conducted by reacting about 1 to about1.5 moles of sodium azide with 1 mole of the compound of the formula(IV) in the presence of about 0.05 to about 1 mole of aluminum chlorideas a catalyst, in a polar solvent such as dimethylformamide.

The reaction in the process (d) can be carried out generally under anormal pressure at a temperature of about 0 to about 200° C., preferablyabout 25 to about 130° C., but it may also be optionally operated underan elevated or reduced pressure.

The process (d) can be conducted by reacting about 2 to about 4 moles oftrimethylsilyl azide with 1 mole of the compound of the formula (V).

The reaction in the process (e) may usually be carried out in a solventwhich is inert to the reaction. Examples of the inert solvents usefulfor the reaction include, for example, water; and alcohols (such asmethanol, ethanol and isopropanol).

The reaction in the process (e) can be carried out in the presence of abase, for example, inorganic bases (such as sodium hydrogencarbonate,potassium hydrogencarbonate, sodium carbonate, potassium carbonate,sodium hydroxide and potassium hydroxide).

The reaction temperature in the process (e) can be set up to usuallyabout -30 to about 50° C., preferably about 0 to about 30° C. Further,the reaction should preferably be carried out under a normal pressure,but it may also be optionally operated under an elevated or reducedpressure.

The process (e) can be conducted by reacting about 1 to about 1.3 molesof the compound of the formula (VII) with 1 mole of the compound of theformula (VI) in the presence of a base in an inert solvent.

The reaction in the process (f) may usually be carried out in a solventwhich is inert to the reaction. Examples thereof include, for example,water; alcohols (such as ethanol); ethers (such as dioxane) and carbontetrachloride.

The reaction temperature in the process (f) is usually about -30 toabout 50° C., preferably about 0 to about 40° C. The reaction shouldpreferably be carried out under a normal pressure, but it may also beoptionally operated under an elevated or reduced pressure.

The process (f) can be conducted by reacting about 2 to about 3 moles ofsodium periodate with 1 mole of the compound of the formula (VIII) inthe presence of a catalytic amount of osmium oxide [OsO₄ ].

The active compounds of formula (I) according to the invention have, asshown in the test examples afterward, excellent herbicidal activity sothat they can be used as agrochemicals, particularly herbicides forcontrolling weeds. The term "weeds" means all plants which grow inundesired loci.

The compounds according to the invention act as non-selective orselective herbicides in dependence on the concentration used.

The active compounds according to the invention can be used, forexample, as selective herbicides in connection with the following weedsand the cultivated plants.

Dicotyledon Weeds of the Genera

Sinapis, Lepidium, Galium, Stellaria, Chenopodium, Urtica, Senecio,Amaranthus, Portulaca, Xanthium, Ipomoea, Polygonum, Ambrosia, Cirsium,Sonchus, Solanum, Rorippa, Lamium, Veronica, Datura, Viola, Galeopsis,Papaver, Centaurea, Galinsoga, Rotala, Lindernia, etc.

Dicotyledon Cultures of the Genera

Gossypium, Glycine, Beta, Daucus, Phaseolus, Pisum, Solanum, Linum,Ipomoea, Vicia, Nicotiana, Lycopersicon, Arachis, Brassica, Lactuca,Cucumis, Cucurbita, etc.

Monocotyledon Weeds of the Genera

Echinochloa, Setaria, Panicum, Digitaria, Phleum, Poa, Festuca,Eleusine, Lolium, Bromus, Avena, Cyperus, Sorghum, Agropyron,Monochoria, Fimbristylis, Sagittaria, Eleocharis, Scirpus, Paspalum,Ischaemum, Agrostis, Alopecurus, Cynodon, etc.

Monocotyledon Cultures of the Genera

Oryza, Zea, Triticum, Hordeum, Avena, Secale, Sorghum, Panicum,Saccharum, Ananas, Asparagus, Allium, etc.

However, the use of the active compounds of the formula (I) according tothe invention is in no way restricted to the above genera, but alsoextends in the same manner to other plants. Further, the activecompounds of the invention are suitable, depending on the concentration,for the total combating of weeds, for example on industrial terrain,rail tracks, and on paths and squares with or without tree plantings.

Equally, the active compounds of the invention can be employed forcombating weeds in perennial cultures, for example afforestations,decorative tree plantations, orchards, vineyards, citrus groves, nutsorchards, banana plantations, coffee plantations, tea plantations,rubber plantations, oil palm plantations, cocoa plantations, soft fruitand plantations and hopfields, and for the selective combating of weedsin annual cultures.

The active compounds of the formula (I) according to the invention canbe converted to the customary formulations, such as solutions,emulsions, wettable powders, suspensions, powders, soluble powders,granules, tablets, suspension-emulsion concentrates, very fine capsulesin polymeric substances, natural and synthetic materials impregnatedwith active compound, etc.

These formulations are produced in the manner known per se, for example,by mixing the active compounds with extenders, such as liquid solventsand/or solid carriers, optionally with the use of surface-active agents,such as emulsifying agents and/or dispersing agents and/or foam-formingagents.

Suitable liquid solvents include: aromatic hydrocarbons, such as xylene,toluene or alkyl naphthalenes; chlorinated aromatic hydrocarbons andchlorinated aliphatic hydrocarbons, such as chlorobenzenes,chloroethylenes or methylene chloride; aliphatic hydrocarbons, such ascyclohexane or paraffins, for example petroleum fractions, mineral andvegetable oils; alcohols, such as butanol or glycol as well as theirethers and esters, ketones, such as acetone, methyl ethyl ketone, methylisobutyl ketone or cyclohexanone; strongly polar solvents, such asdimethylformamide and dimethylsulfoxide; as well as water. When water isused as an extender, organic solvents can be used as auxiliary solvents.

Suitable solid carriers include: ammonium salts and ground naturalminerals, such as kaolins, clays, talc, chalk, quartz, attapulgite,montmorillonite or diatomaceous earth, and ground synthetic minerals,such as highly disperse silicic acid, alumina and silicates. Suitablesolid carriers for granules include: for example, crushed andfractionated natural rocks such as calcite, marble, pumice, sepioliteand dolomite, as well as synthetic granules of inorganic and organicmeals, and granules of organic material such as sawdust, coconut shells,maize cobs and tobacco stalks.

Suitable emulsifying and/or foam-forming agents include: for examplenon-ionic and anionic emulsifiers, such as polyoxyethylene-fatty acidesters, polyoxyethylene-fatty alcohol ethers, for example alkylarylpolyglycol ethers, alkylsulfonates, alkylsulfates, arylsulfonates aswell as albumin hydrolysation products.

Suitable dispersing agents include: for example lignin-sulphite wasteliquors and methylcellulose.

Adhesives may also be optionally used in formulations include powders,granules, natural and synthetic materials impregnated with activecompound or emulsions. The following are examples of such adhesives:carboxymethylcellulose and natural and synthetic polymers such as gumarabic, polyvinyl alcohol and polyvinyl acetate, as well as naturalphospholipids, such as cephalins and lecithins, synthetic phospholipids.Additionally, mineral and vegetable oils can also be used as furtheradditives.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian Blue; and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs and metal phthalocyaninedyestuffs, and trace nutrients such as salts of metals, for exampleiron, manganese, boron, copper, cabalt, molybdenum and zinc.

The formulations in general contain between 0.1 and 95 per cent byweight preferably between 0.5 and 90% by weight of the active compound.

The active compounds of the invention can be used for controlling ofweeds as they are or in a form of such formulations and can be mixedwith any of known herbicides. The mixture may be either prepared inadvance in the form of a final formulation or prepared by tank-mixingimmediately before use.

It is possible to mix the active compounds of the formula (I) accordingto the invention with a chemical injury-mitigating agent and thusbroading the applicability of the instant compounds as a selectiveherbicide.

The chemical injury-mitigating agent may be exemplified by1-(α,α-dimethylbenzyl)-3-p-tolyl urea.

The active compounds of the formula (I) according to the invention maybe applied as they are or in the above form of the formulations, by anyof conventional methods such as watering, spraying, atomizing, powderspreading or granule scattering.

The active compounds of the formula (I) according to the invention maybe applied at any stage of preemergence or postemergence. Also, they canbe incorporated into the soil before sowing.

The application amount of the active compound is not strictly limitedand may be varied within a wide range depending on the desired effect,the kind of target plant(s) as the object, the location of application,the time of application and the like but, as a tentative measure, forexample, the amount can be exemplified by about 0.001 kg/ha to about 10kg/ha, preferably about 0.01 kg/ha to about 5 kg/ha of the activecompound.

The following examples illustrate the production and uses of theinventive compounds, but they should not be regarded as limiting theinvention in any way. The term "part(s)" therein means "part(s) byweight" unless otherwise noted.

EXAMPLES Synthesis Example 1 ##STR17##

0.6 g of 1-(3-isooxazolylmethyl)-5(4H)-tetrazolinone, 0.5 g of4-dimethylaminopyridine and 0.8 g of N-isopropyl-N-phenylcarbamoylchloride were suspended in 30 ml of toluene and the suspension wasstirred for 5 hours at 50-55° C. After allowing to cool off, the organiclayer was washed successively with water, 1N hydrochloric acid, waterand brine. After drying the organic layer over anhydrous sodium sulfate,the solvent was distilled off under reduced pressure and the residue waspurified by column chromatography (ethanol/chloroform=2/100) to obtain1.0 g of1-(3-isoxazolylmethyl)-4-(N-isopropyl-N-phenylcarbamoyl)-5(4H)-tetrazolinone.m.p.: 110-112° C.

Synthesis Example 2 ##STR18##

0.4 g of1-(4-chloro-1,3-dimethyl-5-pyrazolylmethyl)-5(4H)-tetrazolinone, 0.26 gof 4-dimethylaminopyridine and 0.41 g of N-isopropyl-N-phenylcarbamoylchloride were suspended in 50 ml of toluene and the suspension wasstirred for 5 hours at 50-55° C. After allowing to cool off, the organiclayer was washed successively with water, 1N hydrochloric acid, waterand brine. After drying the organic layer over anhydrous sodium sulfate,the solvent was distilled off under reduced pressure and the residue waspurified by column chromatography (ethanol/chloroform=2/150) to obtain0.6 g of1-(4-chloro-1,3-dimethyl-5-pyrazolylmethyl)-4-(N-isopropyl-N-phenylcarbamoyl)-5(4H)-tetrazolinone.m.p.: 158-159.5° C.

Synthesis Example 3 ##STR19##

0.6 g of 1-cyclohexylmethyl-5(4H)-tetrazolinone, 0.45 g of4-dimethylaminopyridine and 0.72 g of N-isopropyl-N-phenylcarbamoylchloride were suspended in toluene and the suspension was stirred for 5hours at 50-55° C. After allowing to cool off, the organic layer waswashed successively with water, 1N hydrochloric acid and brine. Afterdrying the organic layer over anhydrous sodium sulfate, the solvent wasdistilled off under reduced pressure and the residue was purified bycolumn chromatography (chloroform: 100%) to obtain 0.9 g of1-cyclohexyl-methyl-4-(N-isopropyl-N-phenylcarbamoyl)-5(4H)-tetrazolinone.m.p.: 79-81.5° C.

Synthesis Example 4 ##STR20##

0.7 g of 1-cyclopropylmethyl-5(4H)-tetrazolinone, 0.8 g of4-dimethylaminopyridine and 0.8 g of N-isopropyl-N-phenylcarbamoylchloride were suspended in toluene and the suspension was stirred for 6hours at 50-55° C. After allowing to cool off, the organic layer waswashed successively with water, diluted hydrochloric acid and brine anddried over anhydrous magnesium sulfate. The solvent was distilled offunder reduced pressure and the residue was purified by columnchromatography on silica gel (chloroform) to obtain 1.4 g of1-cyclopropylmethyl-4-(N-isopropyl-N-phenylcarbamoyl)-5(4H)-tetrazolinone. m.p.: 67-69° C.

Table 1 shows the compounds of the formula (I) according to theinvention obtained in the same manner as those of the above SynthesisExamples 1-4, together with the compounds obtained in the aboveSynthesis Examples 1-4.

                                      TABLE 1                                     __________________________________________________________________________     ##STR21##                                      (I)                           Compound No.                                                                         R.sup.1                                                                                    ##STR22##                                                                        R.sup.2                                                                             ##STR23##                                                                            R.sup.3                                                                            m.p. (°  C.) or                                                        n.sub.D.sup.20                       __________________________________________________________________________     1                                                                                    ##STR24##  --  C.sub.3 H.sub.7 -iso                                                                ##STR25##   110-112                               2                                                                                    ##STR26##  --  C.sub.3 H.sub.7 -iso                                                                ##STR27##   1.5276                                3                                                                                    ##STR28##  --  C.sub.3 H.sub.7 -iso                                                                ##STR29##                                         4                                                                                    ##STR30##  --  C.sub.3 H.sub.7 -iso                                                                ##STR31##                                         5                                                                                    ##STR32##  --  C.sub.3 H.sub.7 -iso                                                                ##STR33##                                         6                                                                                    ##STR34##  --                                                                                 ##STR35##          111-115.5                           7                                                                                    ##STR36##  --                                                                                 ##STR37##                                              8                                                                                    ##STR38##  --                                                                                 ##STR39##                                              9                                                                                    ##STR40##  --  C.sub.2 H.sub.5                                                                     ##STR41##                                        10                                                                                    ##STR42##  --  C.sub.2 H.sub.5                                                                    C.sub.3 H.sub.7 -iso                              11                                                                                    ##STR43##  --  C.sub.2 H.sub.5                                                                     ##STR44##                                        12                                                                                    ##STR45##  --  CH.sub.3                                                                           C.sub.3 H.sub.7 -iso                              13                                                                                    ##STR46##  --  C.sub.2 H.sub.5                                                                    C.sub.2 H.sub.5                                   14                                                                                    ##STR47##  --  C.sub.3 H.sub.7 -iso                                                                ##STR48##   84-86                                15                                                                                    ##STR49##  --  C.sub.3 H.sub.7 -iso                                                                ##STR50##   106-109                              16                                                                                    ##STR51##  --  C.sub.3 H.sub.7 -iso                                                                ##STR52##                                        17                                                                                    ##STR53##  --  C.sub.2 H.sub.5                                                                     ##STR54##                                        18                                                                                    ##STR55##  --  C.sub.2 H.sub.5                                                                    C.sub.3 H.sub.7 -iso                                                                       1.5012                               19                                                                                    ##STR56##  --  C.sub.2 H.sub.5                                                                     ##STR57##                                        20                                                                                    ##STR58##  --  C.sub.2 H.sub.5                                                                    C.sub.2 H.sub.5                                   21                                                                                    ##STR59##  --  C.sub.3 H.sub.7 -iso                                                                ##STR60##   88-92                                22                                                                                    ##STR61##  --  C.sub.3 H.sub.7 -iso                                                                ##STR62##                                        23                                                                                    ##STR63##  --  C.sub.3 H.sub.7 -iso                                                                ##STR64##                                        24                                                                                    ##STR65##  --  C.sub.3 H.sub.7 -iso                                                                ##STR66##                                        25                                                                                    ##STR67##  --  C.sub.2 H.sub.5                                                                     ##STR68##                                        26                                                                                    ##STR69##  --  C.sub.2 H.sub.5                                                                    C.sub.2 H.sub.5                                   27                                                                                    ##STR70##  --  C.sub.2 H.sub.5                                                                    C.sub.3 H.sub.7 -iso                                                                       1.5037                               28                                                                                    ##STR71##  --  C.sub.2 H.sub.5                                                                     ##STR72##                                        29                                                                                    ##STR73##  --                                                                                 ##STR74##        151.5-152.5                          30                                                                                    ##STR75##  --  C.sub.3 H.sub.7 -iso                                                                ##STR76##   1.5441                               31                                                                                    ##STR77##  --  C.sub.3 H.sub.7 -iso                                                                ##STR78##                                        32                                                                                    ##STR79##  --  C.sub.3 H.sub.7 -iso                                                                ##STR80##                                        33                                                                                    ##STR81##  --  C.sub.3 H.sub.7 -iso                                                                ##STR82##                                        34                                                                                    ##STR83##  --  C.sub.2 H.sub.5                                                                     ##STR84##                                        35                                                                                    ##STR85##  --  C.sub.2 H.sub.5                                                                    C.sub.2 H.sub.5                                   36                                                                                    ##STR86##  --  C.sub.2 H.sub.5                                                                    C.sub.3 H.sub.7 -iso                              37                                                                                    ##STR87##  --  C.sub.2 H.sub.5                                                                     ##STR88##                                        38                                                                                    ##STR89##  --  C.sub.3 H.sub.7 -iso                                                                ##STR90##     112-116.5                          39                                                                                    ##STR91##  --  C.sub.3 H.sub.7 -iso                                                                ##STR92##                                        40                                                                                    ##STR93##  --  C.sub.3 H.sub.7 -iso                                                                ##STR94##                                        41                                                                                    ##STR95##  --  C.sub.2 H.sub.5                                                                     ##STR96##                                        42                                                                                    ##STR97##  --  CH.sub.3                                                                           C.sub.3 H.sub.7 -iso                              43                                                                                    ##STR98##  --  C.sub.3 H.sub.7 -iso                                                                ##STR99##   158.5-159.5                          44                                                                                    ##STR100## --  C.sub.3 H.sub.7 -iso                                                                ##STR101##                                       45                                                                                    ##STR102## --  C.sub.3 H.sub.7 -iso                                                                ##STR103##                                       46                                                                                    ##STR104## --  C.sub.2 H.sub.5                                                                     ##STR105##                                       47                                                                                    ##STR106## --                                                                                 ##STR107##                                            48                                                                                    ##STR108## --                                                                                 ##STR109##                                            49                                                                                    ##STR110## --  C.sub.2 H.sub.5                                                                     ##STR111##                                       50                                                                                    ##STR112## --  C.sub.3 H.sub.7 -iso                                                                ##STR113##    92-97.5                            51                                                                                    ##STR114## --  C.sub.3 H.sub.7 -iso                                                                ##STR115##    119-121.5                          52                                                                                    ##STR116## --  C.sub.3 H.sub.7 -iso                                                                ##STR117##                                       53                                                                                    ##STR118## --  C.sub.2 H.sub.5                                                                     ##STR119##                                       54                                                                                    ##STR120## --                                                                                 ##STR121##                                            55                                                                                    ##STR122## --                                                                                 ##STR123##                                            56                                                                                    ##STR124## --  C.sub.2 H.sub.5                                                                     ##STR125##                                       57                                                                                    ##STR126## --  C.sub.3 H.sub.7 -iso                                                                ##STR127##  1.5312                               58                                                                                    ##STR128## --  C.sub.3 H.sub.7 -iso                                                                ##STR129##                                       59                                                                                    ##STR130## --  C.sub.3 H.sub.7 -iso                                                                ##STR131##                                       60                                                                                    ##STR132## --  C.sub.3 H.sub.7 -iso                                                                ##STR133##                                       61                                                                                    ##STR134## --  C.sub.3 H.sub.7 -iso                                                                ##STR135##                                       62                                                                                    ##STR136## --  C.sub.2 H.sub.5                                                                     ##STR137##                                       63                                                                                    ##STR138## --                                                                                 ##STR139##                                            64                                                                                    ##STR140## --                                                                                 ##STR141##                                            65                                                                                    ##STR142## --  C.sub.3 H.sub.7 -iso                                                                ##STR143##  oily                                 66                                                                                    ##STR144## --  C.sub.3 H.sub.7 -iso                                                                ##STR145##                                       67                                                                                    ##STR146## --  C.sub.3 H.sub.7 -iso                                                                ##STR147##                                       68                                                                                    ##STR148## --  C.sub.3 H.sub.7 -iso                                                                ##STR149##                                       69                                                                                    ##STR150## --  C.sub.2 H.sub.5                                                                     ##STR151##                                       70                                                                                    ##STR152## --                                                                                 ##STR153##                                            71                                                                                    ##STR154## --                                                                                 ##STR155##                                            72                                                                                    ##STR156## --                                                                                 ##STR157##                                            73                                                                                    ##STR158## --  C.sub.3 H.sub.7 -iso                                                                ##STR159##  112.5-114.5                          74                                                                                    ##STR160## --  C.sub.3 H.sub.7 -iso                                                                ##STR161##                                       75                                                                                    ##STR162## --  C.sub.2 H.sub.5                                                                    C.sub.2 H.sub.5                                                                            96-98                                76                                                                                    ##STR163## --                                                                                 ##STR164##                                            77                                                                                    ##STR165## --  C.sub.3 H.sub.7 -iso                                                                ##STR166##  67-69                                78                                                                                    ##STR167## --  C.sub.3 H.sub.7 -iso                                                                ##STR168##                                       79                                                                                    ##STR169## --  C.sub.3 H.sub.7 -iso                                                                ##STR170##                                       80                                                                                    ##STR171## --  C.sub.3 H.sub.7 -iso                                                                ##STR172##                                       81                                                                                    ##STR173## --  C.sub.2 H.sub.5                                                                     ##STR174##                                       82                                                                                    ##STR175## --                                                                                 ##STR176##       111-113                              83                                                                                    ##STR177## --                                                                                 ##STR178##                                            84                                                                                    ##STR179## --                                                                                 ##STR180##                                            85                                                                                    ##STR181## --  C.sub.3 H.sub.7 -iso                                                                ##STR182##    85-85.5                            86                                                                                    ##STR183## --  C.sub.3 H.sub.7 -iso                                                                ##STR184##                                       87                                                                                    ##STR185## --  C.sub.3 H.sub.7 -iso                                                                ##STR186##                                       88                                                                                    ##STR187## --  C.sub.3 H.sub.7 -iso                                                                ##STR188##                                       89                                                                                    ##STR189## --  C.sub.2 H.sub.5                                                                     ##STR190##                                       90                                                                                    ##STR191## --                                                                                 ##STR192##                                            91                                                                                    ##STR193## --                                                                                 ##STR194##                                            92                                                                                    ##STR195## --                                                                                 ##STR196##                                            93                                                                                    ##STR197## --  C.sub.3 H.sub.7 -iso                                                                ##STR198##  1.5303                               94                                                                                    ##STR199## --  C.sub.3 H.sub.7 -iso                                                                ##STR200##                                       95                                                                                    ##STR201## --  C.sub.2 H.sub.5                                                                     ##STR202##                                       96                                                                                    ##STR203## --                                                                                 ##STR204##                                            97                                                                                    ##STR205## --                                                                                 ##STR206##                                            98                                                                                    ##STR207## --  C.sub.2 H.sub.5                                                                     ##STR208##                                       99                                                                                    ##STR209## --  C.sub.2 H.sub.5                                                                     ##STR210##                                       100                                                                                   ##STR211## --  C.sub.3 H.sub.7 -iso                                                                ##STR212##    79-81.5                            101                                                                                   ##STR213## --  C.sub.3 H.sub.7 -iso                                                                ##STR214##                                       102                                                                                   ##STR215## --  C.sub.3 H.sub.7 -iso                                                                ##STR216##  1.5329                               103                                                                                   ##STR217## --  C.sub.3 H.sub.7 -iso                                                                ##STR218##  92.5-95.5                            104                                                                                   ##STR219## --  C.sub.3 H.sub.7 -iso                                                                ##STR220##    69-72.5                            105                                                                                   ##STR221## --  C.sub.3 H.sub.7 -iso                                                                ##STR222##                                       106                                                                                   ##STR223## --  C.sub.3 H.sub.7 -iso                                                                ##STR224##  83.5-85                              107                                                                                   ##STR225## --  C.sub.2 H.sub.5                                                                     ##STR226##                                       108                                                                                   ##STR227## --  C.sub.2 H.sub.5                                                                     ##STR228##  1.5023                               109                                                                                   ##STR229## --  C.sub.3 H.sub.7 -iso                                                                ##STR230##                                       110                                                                                   ##STR231## --  CH.sub.3                                                                            ##STR232##                                       111                                                                                   ##STR233## --  C.sub.2 H.sub.5                                                                    C.sub.2 H.sub.5                                   112                                                                                   ##STR234## --  C.sub.2 H.sub.5                                                                    C.sub.3 H.sub.7 -iso                              113                                                                                   ##STR235## --  C.sub.3 H.sub.7 -iso                                                                ##STR236##                                       114                                                                                   ##STR237## --  C.sub.3 H.sub.7 -iso                                                                ##STR238##                                       115                                                                                   ##STR239## --  C.sub.3 H.sub.7 -iso                                                                ##STR240##                                       116                                                                                   ##STR241## --  C.sub.3 H.sub.7 -iso                                                                ##STR242##                                       117    CH.sub.3 S  CH.sub.2                                                                          C.sub.3 H.sub.7 -iso                                                                ##STR243##  62-66                                118    CH.sub.3 S  --  C.sub.3 H.sub.7 -iso                                                                ##STR244##  1.5485                               119    CH.sub.3 S  --  C.sub.3 H.sub.7 -iso                                                                ##STR245##  1.5333                               120    CH.sub.3 S(O)                                                                             --  C.sub.3 H.sub.7 -iso                                                                ##STR246##  1.5453                               121    CH.sub.3 SO.sub.2                                                                         --  C.sub.3 H.sub.7 -iso                                                                ##STR247##  84-87                                122    n-C.sub.3 H.sub.7 S                                                                       --  C.sub.3 H.sub.7 -iso                                                                ##STR248##    54-54.5                            123    iso-C.sub.3 H.sub.7 S                                                                     --  C.sub.3 H.sub.7 -iso                                                                ##STR249##  1.5387                               124    C.sub.2 H.sub.5 S                                                                         --  C.sub.3 H.sub.7 -iso                                                                ##STR250##                                       125                                                                                   ##STR251## --  C.sub.3 H.sub.7 -iso                                                                ##STR252##  1.5289                               126                                                                                   ##STR253## CH.sub.2                                                                          C.sub.3 H.sub.7 -iso                                                                ##STR254##  76.5-79.5                            127                                                                                   ##STR255## CH.sub.2                                                                          C.sub.3 H.sub.7 -iso                                                                ##STR256##                                       128                                                                                   ##STR257##                                                                                ##STR258##                                                                       C.sub.3 H.sub.7 -iso                                                                ##STR259##  1.5201                               129                                                                                   ##STR260##                                                                                ##STR261##                                                                       C.sub.3 H.sub.7 -iso                                                                ##STR262##                                       __________________________________________________________________________

Synthesis Example 5 ##STR263##

0.8 g of1-(2-propenyl)-4-(N-isopropyl-N-phenylcarbamoyl)-5(4H)-tetrazolinone and1.5 g of m-chloroperoxybenzoic acid were dissolved in 50 ml of methylenechloride and the mixture was stirred for 6 hours at room temperature.After washing the reaction mixture with water, the organic layer wasdried over anhydrous sodium sulfate. Then, the solvent was distilled offunder reduced pressure and the residue was purified by columnchromatography (chloroform) to obtain 0.5 g of1-(2,3-epoxypropyl)-4-(N-isopropyl-N-phenylcarbamoyl)-5(4H)tetrazolinone.n₂₀ ^(D) : 1.5289

Synthesis Example 6 ##STR264##

A toluene (10 ml) solution of nitroethane (0.4 g) and triethylamine (0.9g) was added at ambient temperature to a stirring toluene (20 ml)solution of1-(3-butenyl)-4-(N-iso-propyl-N-phenylcarbamoyl)-5(4H)-tetrazolinone(1.0 g) and phenylisocyanate (0.9 g) and stirred for 18 hours. Afterremoving the precipitate from the reaction mixture by filtration, thetoluene solution was washed with water, diluted hydrochloric acid andwater, dried over magnesium sulfate, and evaporated. The residue waspurified by column chromatography on silica gel (n-hexane:ethylacetate=1:1) to obtain1-[2-(3-methyl-2-isoxazolin-5-yl)ethyl]-4-(N-iso-propyl-N-phenylcarbamoyl)-5-(4H)tetrazolinone(0.7 g). m.p.: 76.5-79.5° C.

Synthesis Example 7 ##STR265##

3.9 g of 3-isoxazolylmethyl isocyanate, 7.5 g of trimethylsilyl azideand a catalytic amount of boron trifluoride-ether complex were mixed andthe mixture was heated under reflux for 40 hours. After allowing to cooloff, excessive trimethylsilyl azide was distilled off under reducedpressure. To the residue, methanol was added. Thereafter, methanol wasdistilled off under reduced pressure and the residue was purified bycolumn chromatography (ethanol/chloroform=10/100) to obtain 4.5 g of1-(3-isoxazolylmethyl)-5(4H)-tetrazolinone. m.p.: 76-79° C.

Synthesis Example 8 ##STR266##

5.0 g of 4-chloro-5-chloromethyl-1,3-dimethylpyrazole, 3.0 g of4-dimethylaminopyridine and 2.5 g of 1-ethenyl-5(4H)-tetrazolinone weresuspended in 100 ml of acetonitrile and the suspension was stirred for 5hours at 50-55° C. After allowing to cool off the solvent was distilledoff under reduced pressure. After adding 100 ml of water, the mixturewas extracted with methylene chloride, and the organic layer was washedsuccessively with water, 1N hydrochloric acid, water and saturatedsaline. After drying the organic layer over anhydrous sodium sulfate,the solvent was distilled off under reduced pressure and the residue waspurified by column chromatography (ethanol/chloroform=2/100) to obtain4.2 g of1-(4-chloro-1,3-dimethyl-5-pyrazolylmethyl)-4-ethenyl-5(4H)-tetrazolinone.m.p.: 78-79.5° C.

Synthesis Example 9 ##STR267##

0.6 g of1-(4-chloro-1,3-dimethyl-5-pyrazolylmethyl)-4-ethenyl-5(4H)-tetrazolinonewas suspended in 30 ml of dioxane and 10 ml of water. A catalytic amountof osmium oxide [OsO₄ ] was added and the mixture was vigorously stirredfor 30 minutes. Then, 1.5 g of sodium periodate was further added andthe mixture was stirred for 12 hours. The reaction mixture was filteredoff and the solvent was distilled off under reduced pressure until theamount of the filtrate was reduced to 1/4. After adding 50 ml of water,the mixture was extracted with methylene chloride. The organic layer wasdried over anhydrous sodium sulfate and then the solvent was distilledoff under reduced pressure to obtain 0.4 g of1-(4-chloro-1,3-dimethyl)-5-pyrazolylmethyl)-5(4H)-tetrazolinone. m.p.:157-158.5° C.

Synthesis Example 10 ##STR268##

6.0 g of cyclohexylmethyl isocyanate, 10 g of trimethylsilyl azide and acatalytic amount of boron trifluoride-ether complex were mixed and themixture was heated under reflux for 50 hours. After allowing to cooloff, excessive trimethylsilyl azide was distilled off under reducedpressure. To the residue, methanol was added. Thereafter, methanol wasdistilled off under reduced pressure and then the residue was purifiedby column chromatography (chloroform=100%) to obtain 9.8 g of1-cyclohexylmethyl-5(4H)-tetrazolinone. m.p.: 88-89° C.

Synthesis Example 11 ##STR269##

To a methanol solution of 14.2 g of cyclopropylmethylamine and 22.5 g ofpotassium tert-butoxide, 20 g of carbon disulfide was added dropwiseunder cooling with ice. After 30 minutes, 25.2 g of dimethyl sulfate wasadded thereto under the same condition as above and the reaction wasconducted for 1 hour. After adding water to the reaction solution, themixture was extracted with toluene and the toluene layer was washed withwater. After drying the toluene solution with anhydrous magnesiumsulfate, toluene was distilled off to obtain 26.3 g of methylcyclopropylmethyldithiocarbamate. To the dithiocarbamate thus obtained,an aqueous solution of 12.7 g of sodium azide was added and reacted at100° C. until the evolution of methylmercaptan was ceased. Afterallowing to cool off, the reaction solution was washed with ethylacetate. To the aqueous layer, ethyl acetate was added, acidified withdiluted hydrochloric acid and then the acidic materials were extractedwith ethyl acetate. The ethyl acetate solution was washed with saturatedsaline, dried over anhydrous magnesium sulfate and then ethyl acetatewas distilled off under reduced pressure to obtain 10 g of1-cyclopropylmethyl-4-H-tetrazolin-5-thione. The product was dissolvedin 10 ml of an aqueous solution of 3.2 g of sodium hydroxide and 6 g ofpropylene oxide was added thereto under cooling with ice. The reactionsolution was stirred overnight. Then, the reaction solution wasacidified with concentrated hydrochloric acid and extracted withchloroform. The organic layer was washed with saturated saline and driedover anhydrous magnesium sulfate. After distilling off the solvent, theresidue was purified by column chromatography on silica gel(n-hexane/ethyl acetate=1:1) to obtain 5.0 g of1-cyclopropylmethyl-5(4H)-tetrazolinone. m.p.: 61-64° C.

Synthesis Example 12 ##STR270##

A mixture of 5.6 g of cyclopentylidene acetic acid chloride and 9.8 g oftrimethylsilyl azide was heated under reflux at 100-130° C. for 48hours. After allowing to cool off, unreacted trimethylsilyl azide wasdistilled off under reduced pressure. To the residue, methanol wasadded. Methanol was distilled off under reduced pressure and the residuewas purified by column chromatography on silica gel (n-hexane/ethylacetate=2:1-1:1) to obtain, as a by-product, 0.7 g of1-(1-cyclopentenylmethyl)-5(4H)-tetrazolinone. The main product was 3.2g of 1-cyclopentylidenemethyl-5(4H)-tetrazolinone. m.p.: 91-93° C.

Table 2 shows the compounds of formula (II) obtained in a manner similarto those of Synthesis Examples 7 and 9-12, together with the compoundsobtained in Synthesis Examples 7 and 9-12.

                  TABLE 2                                                         ______________________________________                                         ##STR271##                   (II)                                            Compound  No.                                                                         R.sup.1                                                                                        ##STR272##                                                                           m.p. (° C.) or n.sub.D.sup.20          ______________________________________                                        II.1                                                                                   ##STR273##     --      61-64                                         II.2                                                                                   ##STR274##     --      91-93                                         II.3                                                                                   ##STR275##     --      88-89                                         II.4                                                                                   ##STR276##     --      1.4989                                        II.5                                                                                   ##STR277##     --      76-79                                         II.6                                                                                   ##STR278##     --      150-152                                       II.7                                                                                   ##STR279##     --      124-128                                       II.8                                                                                   ##STR280##     --      1.5120                                        II.9                                                                                   ##STR281##     --                                                    II.10                                                                                  ##STR282##     --      157-158.5                                     II.11                                                                                  ##STR283##     --      138-140.5                                     II.12                                                                                  ##STR284##     --      1.5073                                        II.13                                                                                  ##STR285##     --      oily                                          II.14                                                                                  ##STR286##     --      141-142.5                                     II.15                                                                                  ##STR287##     --                                                    II.16                                                                                  ##STR288##     --                                                    II.17                                                                                  ##STR289##     --                                                    II.18                                                                                  ##STR290##     --                                                    II.19   CH.sub.2 S      --                                                    II.20   CH.sub.2 S      CH.sub.2                                              II.21   CH.sub.3 S(O)   --                                                    II.22   CH.sub.3 SO.sub.2                                                                             --                                                    II.23   C.sub.2 H.sub.5 S                                                                             --                                                    II.24   n-C.sub.3 H.sub.7 S                                                                           --                                                    II.25   iso-C.sub.3 H.sub.7 S                                                                         --                                                    ______________________________________                                    

Table 3 shows the compounds of formula (VIII) obtained in a mannersimilar to that of Synthesis Example 8, together with the compoundsobtained in Synthesis Example 8.

                  TABLE 3                                                         ______________________________________                                         ##STR291##                  (VIII)                                           Compound  No.                                                                         R.sup.1                                                                                        ##STR292##                                                                           m.p. (° C.) or n.sub.D.sup.20          ______________________________________                                        VIII.1                                                                                 ##STR293##     --      59-61.5                                       VIII.2                                                                                 ##STR294##     --      1.5240                                        VIII.3                                                                                 ##STR295##     --      oily                                          VIII.4                                                                                 ##STR296##     --      78-79.5                                       III.5                                                                                  ##STR297##     --      96-99                                         VIII.6                                                                                 ##STR298##     --      76-77.5                                       VIII.7                                                                                 ##STR299##     --      68-72                                         ______________________________________                                    

Test Example 1

Test of pre-emergence soil-treatment against plowed land weeds

Preparing Method

carrier: acetone, 5 parts by weight;

emulsifier: benzyloxy polyglycol ether, 1 part by weight

One part of an active compound is mixed with the above amounts ofcarrier and emulsifier to obtain an emulsion. A prescribed amount ofthis emulsion is diluted with water to prepare testing chemicals.

Testing Procedure

In the greenhouse, seeds of Echinochloa and Amaranthus lividus weresowed each in the surface layer of plowed land soil filled in a 120 cm²pot with soil-covering and a prescribed amount of the above testingchemical was uniformly spread each on the surface layer of soil in thetesting pot. The herbicidal effect was examined on the day after 4 weeksfrom sowing. The herbicidal effect was rated as 100% in the case ofcomplete death and as 0% in the case where equivalent growth wasobserved to the case of an untreated region.

Result

The compounds of No. 1, No. 2, No. 6, No. 14, No. 30, No. 43, No. 57,No. 65 and No. 77 (as disclosed in Table 1 above) destroyed 100% of thetarget weeds to death by application of 1 kg/ha as the effectivecomponent.

Test Example 2

Test of post-emergence foliage treatment against plowed land weeds

Testing Procedure

In the greenhouse, seeds of Echinochloa and Amaranthus lividus weresowed each in a 120 cm² pot filled with plowed land soil and coveredwith soil. After 10 days from sowing and soil-covering (when the weedswere at 2-foliage stage on average), each a prescribed amount of thechemical prepared similarly to those in above Test Example 1 wasuniformly spread on the foliage part of tested plant in the testing pot.After 3 weeks from spreading, the extent of herbicidal effect wasexamined.

Result

The compounds of No. 1, No. 15, No. 57, No. 65, No 73 and No. 85 (asdisclosed in Table 1 above) destroyed 90% or more of the target weeds todeath by application of 2 kg/ha as the effective component.

Formulation Example 1 (Granules)

Twenty-five parts of water are added to a mixture of 10 parts ofCompound No. 1 (see Table 1 above), 30 parts of bentonite(montmorillonite), 58 parts of talc and 2 parts of lignin sulfonate saltfor well kneading followed by granulating in 10 to 40 mesh using anextrusion-granulator and drying at 40-50° C. to obtain granules.

Formulation Example 2 (Granules)

A rotary mixer is charged with 95 parts of clay mineral particles having0.2 to 2 mm of particle size distribution and 5 parts of Compound No. 14(see Table 1 above) is sprayed therein with a liquid diluent underrotation for uniformly wetting followed by drying at 40-50° C. to givegranules.

Formulation Example 3 (Emulsion)

An emulsion is obtained by mixing 30 parts of Compound No. 1 (see Table1 above), 55 parts of xylene, 8 parts of polyoxyethylene alkyl phenylether and 7 parts of calcium alkylbenzene sulfonate by stirring.

Formulation Example 4 (Wettable Powder)

A wettable powder is prepared by crushing and mixing 15 parts ofCompound No. 15 (see Table 1 above), 80 parts of a mixture (1:5) ofWhite Carbon (fine powder of hydrated amorphous silicon oxide) andpowdery clay, 2 parts of sodium alkylbenzene sulphonate and 3 parts of acondensate of sodium alkylnaphthalene sulfonate and formaldehyde.

Formulation Example 5 (Wettable Granules)

Wettable granules are prepared by thoroughly mixing 20 parts of CompoundNo. 57 (see Table 1 above), 30 parts of sodium lignin sulfonate, 15parts of bentonite and 35 parts of calcined diatomaceous earth powder,then adding water and extruding the resulting mixture through a 0.3 mmscreen followed by drying.

It will be appreciated that the instant specification and the claims areset forth by way of illustration and not limitation, and that variousmodifications and changes may be made without departing from the spiritand scope of the present invention.

What is claimed is:
 1. A compound of the formula ##STR300## wherein R¹represents isoxazole optionally substituted by chloro and/or methyl;R²and R³ represent, independently of one another, C₁₋₄ alkyl, C₃₋₆cycloalkyl or optionally substituted phenyl wherein the substituents arehalogen or C₁₋₄ alkyl or R⁴ represents a hydrogen atom, and n represents0 or
 1. 2. A compound according to claim 1, whereinR¹ representsisooxazolyl, optionally substituted by chloro and methyl: R² and R³represent, independently of one another, C₁₋₃ alkyl, cyclohexyl oroptionally substituted phenyl wherein the substituents are fluoro,chloro, bromo or methyl, or R⁴ represents a hydrogen atom, and nrepresents 0 or
 1. 3. A herbicidal composition, which comprises aneffective amount of a 1-substituted methyltetrazolinone according toclaim 2 and an inert carrier.
 4. A process for combating weeds, whichcomprises applying an effective amount of a 1-substitutedmethyltetrazolinone according to claim 2 to said weeds and/or to ahabitat where they reside.